Keep in mind that your filtration should be 8 to 10 x the volume of your tank if you're considering hang on back (HOB) type filters like Aqua Clear, Whispers.
For canisters it's been suggested that your filtration be 5 to 8 x the volume of your tank. The canister filters can be a bit higher priced too.
It also depends on what type of fish you would like to keep. For Goldfish for example and them being large waste producers I recommend 10 x your tank volume with either filter.
If it were my tank I would probably go with an Aqua Clear 110 = 500gph and an Aqua Clear 70 = 300gph for a total of 800gph. If you're going to stock large fish, you may even consider 2 Aqua Clear 110's for 1000gph. They do have a flow control knob to reduce the flow if necessary.
You don't want your fish to be blown around the tank by the current.